diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerTest.java
index c7826cae7a..840107cd6d 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerTest.java
@@ -269,7 +269,7 @@ private SimplexOptimizer.Observer createCallback(Simplex.TransformFactory factor
                 }
                 out.println();
             } catch (IOException e) {
-                Assertions.fail(e.getMessage());
+                Assertions.fail(e);
             }
 
             final double fAtOptimum = function.value(optimum);
@@ -303,7 +303,7 @@ private SimplexOptimizer.Observer createCallback(Simplex.TransformFactory factor
                     // Blank line between simplexes.
                     out.println();
                 } catch (IOException e) {
-                    Assertions.fail(e.getMessage());
+                    Assertions.fail(e);
                 }
             };
         }
@@ -320,7 +320,7 @@ public void checkAlongLine(int numPoints) {
                 try (PrintWriter out = new PrintWriter(Files.newBufferedWriter(Paths.get(name)))) {
                     checkAlongLine(numPoints, out);
                 } catch (IOException e) {
-                    Assertions.fail(e.getMessage());
+                    Assertions.fail(e);
                 }
             } else {
                 checkAlongLine(numPoints, null);